Ultrasonographic measurements of accessory sex glands, ampullae, and urethra of normal stallions of various size types

Pozor, M.A.; McDonnell, Sue M.

doi:10.1016/s0093-691x(02)01034-8

Cited by 24 publications

(18 citation statements)

References 4 publications

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“…On the other hand, PROS showed anechogenic spaces without sexual stimulation, while in stallion are not normal. The jackass AMP had a glandular appearance with anechogenic spaces, whereas in the stallion they are echogenically homogenous and thinner (Pozor & McDonnell, ). The AMP of the jackass may contribute significantly to seminal plasma production, resulting in jackasses ejaculating a larger volume of semen than stallions.…”

Section: Discussionmentioning

confidence: 99%

Examination of jackass (Equus asinus) accessory sex glands by B‐mode ultrasound and of testicular artery blood flow by colour pulsed‐wave Doppler ultrasound: Correlations with semen production

Gacem

Papas

Catalán

et al. 2020

Reprod Domestic Animals

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The accessory sex glands play a major role in the production of seminal plasma, and testicular artery blood flow seems to strongly influence testicular function. However, very little ultrasound imaging of these organs has been undertaken in donkeys. The present work reports the results of such examinations in five jackasses along the year. The accessory glands were inspected by B‐mode ultrasound while the testicular artery blood flow was assessed by colour pulsed‐wave Doppler ultrasound. The testicular artery was examined at pampiniform plexus (PPT), supratesticular area (ST) and capsular artery (CA). Values were recorded for the total arterial blood flow (TABF), peak systolic velocity (PSV), end‐diastolic velocity (EDV), resistive index (RI), pulsatility index (PI) and time average maximum velocity (TAMV). Semen was obtained and assessed for sperm concentration, viability, abnormalities and motility using a CASA system. The bulbourethral glands, prostate and ductus deferens ampullae were relatively larger than in the stallion. Bulbourethral glands and ampullae sizes were inversely correlated with sperm motility. An reduction in blood flow between the level the PPP and the CA was observed, helping to reduce testis temperature and oxygen pressure. Blood flow at the CA showed the strongest correlation with semen production. PI and RI were positively correlated with the CASA motility variable STR (p = .02, p = .06) and sperm viability (p = .01), while sperm concentration (p = .05) correlated inversely with PSV, EDV, TAMV and TABF. EDV also correlated negatively with the CASA variables VSL, LIN, STR and VAP (p ≤ .05). PI and RI were also negatively correlated with testis length (p = .0093, p = −.0438).

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Section: Discussionmentioning

confidence: 99%

Examination of jackass (Equus asinus) accessory sex glands by B‐mode ultrasound and of testicular artery blood flow by colour pulsed‐wave Doppler ultrasound: Correlations with semen production

Gacem

Papas

Catalán

et al. 2020

Reprod Domestic Animals

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“…The equine urethra can be considered similar to the human urethra in terms of the lumen, histomorphometric conformation (Dellmann & Eurell, ; Wolfe & Moll, ; Pozor & McDonnell, ; Barone, ; Arrighi et al . ) and functional process of micturition (Clark et al .…”

Section: Introductionmentioning

confidence: 99%

“…In general, it should be remarked that a limit of any animal model is an uncertain correlation with humans about changes in mechanical properties owing to age and health conditions. The equine urethra can be considered similar to the human urethra in terms of the lumen, histomorphometric conformation (Dellmann & Eurell, 1998;Wolfe & Moll, 1999;Pozor & McDonnell, 2002;Barone, 2003;Arrighi et al 2004) and functional process of micturition (Clark et al 1987;Ronen, 1994;Brading, 1999). These reasons motivate the selection of horse urethra for investigation of the biomechanical response of the urethra under sphincteric contraction.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of the biomechanics of urethral tissues and structures

Natali

Carniel

Frigo

et al. 2016

Experimental Physiology

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New Findings r What is the central question of this study?Prostheses for treatment of urinary incontinence elicit complications associated with an inadequate mechanical action. This investigation aimed to define a procedure addressed to urethral mechanical characterization. Experimental tests are the basis for constitutive formulation, with a view to numerical modelling for investigation of the interaction between the tissues and a prosthesis. r What is the main finding and its importance?Horse urethra, selected for its histomorphometric similarity to human urethra, was characterized by integrated histological analysis and mechanical tests on the biological tissue and structure, leading to constitutive formulation. A non-linear, anisotropic and time-dependent response was found, representing a valid basis for development of a numerical model to interpret the functional behaviour of the urethra.Urinary dysfunction can lead to incontinence, with an impact on the quality of life. Severe dysfunction can be overcome surgically by the use of an artificial urinary sphincter. Nonetheless, several complications may result from inappropriate functioning of the prosthesis, in many instances resulting from an unsuitable mechanical action of the device on the urethral tissues. Computational models allow investigation of the mechanical interaction between biological tissues and biomedical devices, representing a potential support for surgical practice and prosthesis design. The development of such computational tools requires experimental data on the mechanics of biological tissues and structures, which are rarely reported in the literature. The aim of this study was to provide a procedure for the mechanical characterization of urethral tissues and structures. The experimental protocol included the morphometric and histological analysis of urethral tissues, the mechanical characterization of the response of tissues to tensile and stress-relaxation tests and evaluation of the behaviour of urethral structures by inflation tests. Results from the preliminary experiments were processed, adopting specific model formulations, and also providing the definition of parameters that characterize the elastic and A. N. Natali and others viscous behaviour of the tissues. Different experimental protocols, leading to a comprehensive set of experimental data, allow for a reciprocal assessment of reliability of the investigation approach.

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“…Fig. 3 shows urethral length (8,(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) and diameter (15,(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34), flow rate (35)(36)(37)(38)(39)(40)(41)(42), bladder capacity (25,(43)(44)(45)(46)(47)(48)(49), and bladder pressure (1,35,39,40,43,46,50) for over 100 individuals across 13 species.…”

Section: Resultsmentioning

confidence: 99%

Duration of urination does not change with body size

Yang¹,

Pham²,

Choo³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Many urological studies rely on models of animals, such as rats and pigs, but their relation to the human urinary system is poorly understood. Here, we elucidate the hydrodynamics of urination across five orders of magnitude in body mass. Using high-speed videography and flow-rate measurement obtained at Zoo Atlanta, we discover that all mammals above 3 kg in weight empty their bladders over nearly constant duration of 21 ± 13 s. This feat is possible, because larger animals have longer urethras and thus, higher gravitational force and higher flow speed. Smaller mammals are challenged during urination by high viscous and capillary forces that limit their urine to single drops. Our findings reveal that the urethra is a flow-enhancing device, enabling the urinary system to be scaled up by a factor of 3,600 in volume without compromising its function. This study may help to diagnose urinary problems in animals as well as inspire the design of scalable hydrodynamic systems based on those in nature.urology | allometry | scaling | Bernoulli's principle M edical and veterinary urology often relies on simple, noninvasive methods to characterize the health of the urinary system (1, 2). One of the most easily measured characteristics of the urinary system is its flow rate (3), changes in which may be used to diagnose urinary problems. The expanding prostates of aging males may constrict the urethra, decreasing urine flow rate (4). Obesity may increase abdominal pressure, causing incontinence (5). Studies of these ailments and others often involve animal subjects of a range of sizes (6). A study of urination in zero gravity involved a rat suspended on two legs for long periods of time (7), whereas other studies involve mice (8), dogs (1), and pigs (9). Despite the wide range of animals used in urological studies, the consequences of body size on urination remain poorly understood.The bladder serves a number of functions, as reviewed by Bentley (10). In desert animals, the bladder stores water to be retrieved at a time of need. In mammals, the bladder acts as a waterproof reservoir to be emptied at a time of convenience. This control of urine enables animals to keep their homes sanitary and themselves inconspicuous to predators. Stored urine may even be used in defense, which one knows from handling rodents and pets.Several misconceptions in urology have important repercussions in the interpretation of healthy bladder function. For instance, several investigators state that urinary flow is driven entirely by bladder pressure. Consequently, their modeling of the bladder neglects gravitational forces (11-13). Others, such as Martin and Hillman (14), contend that urinary flow is driven by a combination of both gravity and bladder pressure. In this study, we elucidate the hydrodynamics of urination across animal size, showing the effects of gravity increase with increasing body size. ResultsIn Vivo Experiments. We filmed the urination of 16 animals and obtained 28 videos of urination from YouTube, listed in SI Appendix. Movies ...

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Ultrasonographic measurements of accessory sex glands, ampullae, and urethra of normal stallions of various size types

Cited by 24 publications

References 4 publications

Examination of jackass (Equus asinus) accessory sex glands by B‐mode ultrasound and of testicular artery blood flow by colour pulsed‐wave Doppler ultrasound: Correlations with semen production

Examination of jackass (Equus asinus) accessory sex glands by B‐mode ultrasound and of testicular artery blood flow by colour pulsed‐wave Doppler ultrasound: Correlations with semen production

Experimental investigation of the biomechanics of urethral tissues and structures

Duration of urination does not change with body size

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